Many modern vehicles include passive entry passive start (PEPS) systems that enable an individual to gain entry to the vehicle and/or start the vehicle without the use of a key. These PEPS systems rely on the use of key fobs, smartphones and other mobile communications devices that transmit wireless signals to a wireless communication module in the vehicle. A controller authenticates the signals and then actuates door locks and/or starts the vehicle in response to the signals. On some occasions, the mobile communications devices used to request entry to the vehicle or start the vehicle are unavailable or inoperable. For example, typical mobile communication devices depend on batteries that have a limited lifespan. If the battery is unable to deliver power to the device or unable to deliver sufficient power for wireless signal transmission, the user cannot use the device to secure entry to the vehicle or start the vehicle. Similarly, if the user misplaces the device, the user will lack the ability to enter the vehicle or start the vehicle.